Pipetting device

Abstract

A pipetting device for taking up and dispensing fluid volumes has a displacement device with a displacement mechanism and a displacement housing. The pipetting device has an adjusting device for changing the stroke of the displacement mechanism. The stroke of the displacement mechanism can be adjusted, and the corresponding adjustment value can be displayed by an adjustment indicator. A coupling device, in a use state, couples the adjusting device to a volume indicator and decoupled the adjustment device from the adjustment indicator. In an adjustment state, the adjusting device is coupled to the adjustment indicator and is decoupled from the volume indicator. The adjustment indicator displays an adjustment value for the stroke of the displacement means. The adjustment indicator can be adjusted in an adjustment state, whereas it is fixed in a use state.

What is claimed is: 
     
       1. A pipetting device for taking up and dispensing fluid volumes, comprising:
 a displacement apparatus having a displacement device and a displacement housing, 
 a drive device for moving the displacement device in the displacement housing,
 wherein movement of the displacement device is limited by an upper stop, a lower stop and at least one counter stop of the drive device, so that a stroke of the displacement device is defined, 
 
 a volume indicator for displaying a pipetting volume associated with the stroke of the displacement device and/or correlated with the stroke of the displacement device, 
 an adjusting device to change the stroke of the displacement device, 
 an adjustment indicator for indicating an adjustment value of the stroke of the displacement device, and 
 a coupling device which
 in a use state couples the adjusting device to the volume indicator and decouples the adjusting device from the adjustment indicator, whereby an actuation of the adjusting device causes a change of the volume indicator but not of the adjustment indicator, and 
 in an adjustment state couples the adjusting device to the adjustment indicator and decouples the adjusting device from the volume indicator, whereby an actuation of the adjusting device causes a change of the adjustment indicator but not of the volume indicator. 
 
 
     
     
       2. Pipetting device according to  claim 1 , wherein the displacement device is a piston and the displacement housing is a cylinder. 
     
     
       3. Pipetting device according to  claim 1 , wherein the adjusting device is configured to change the stroke of the displacement device by changing the position of the upper stop. 
     
     
       4. Pipetting device according to  claim 3 , wherein, in the use state and in the adjustment state, the adjusting device is coupled to the upper stop, whereby an actuation of the adjusting device causes a change in the position of the upper stop, wherein a force exerted on the adjusting device is transmitted to the upper stop. 
     
     
       5. Pipetting device according to  claim 1 , wherein, in a calibration state, the adjusting device is coupled to the volume indicator and decoupled from the upper stop and from the adjustment indicator, whereby an actuation of the adjusting device causes a change of the volume indicator but not of the adjustment indicator and not of the position of the upper stop. 
     
     
       6. Pipetting device according to  claim 1 , wherein the coupling device comprises:
 at least one first gear wheel coupled to the adjusting device, 
 at least one second gear wheel which can be coupled to the volume indicator, and 
 at least one third gear wheel which can be coupled to the adjustment indicator, 
 
       wherein the first, second and third gear wheels are arranged to rotate about a common axis and to be displaced along said common axis. 
     
     
       7. Pipetting device according to  claim 1 , wherein the adjustment indicator comprises at least one numerical wheel that is rotatable about a longitudinal axis of the pipetting device and that indicates a scale for an adjustment value of the stroke of the displacement device. 
     
     
       8. Pipetting device according to  claim 1 , wherein the pipetting device further comprises an externally accessible actuating element for adjusting the coupling device, wherein adjusting of the coupling device by the actuating element enables a change between the use state and the adjustment state. 
     
     
       9. Pipetting device according to  claim 8 , wherein the actuating element is formed separately from the adjusting device. 
     
     
       10. Pipetting device according to  claim 8 , wherein the adjusting device comprises the actuating element. 
     
     
       11. Pipetting device according to  claim 8 , wherein an adjustment sleeve of the adjusting device forms the actuating element, and wherein the adjustment sleeve is rotatable about a longitudinal axis of the pipetting device for changing the stroke of the displacement device and for changing the volume indicator. 
     
     
       12. Pipetting device according to  claim 8 , wherein an adjustment sleeve of the adjusting device forms the actuating element and wherein the adjustment sleeve is movable along the longitudinal axis of the pipetting device for adjusting the coupling device into the use state and/or adjustment state. 
     
     
       13. Pipetting device according to  claim 8 , wherein an adjustment sleeve of the adjusting device forms the actuating element and wherein the adjustment sleeve is releasably fixable in axially different positions by a holding device of the pipetting device. 
     
     
       14. Pipetting device according to  claim 8 , wherein the coupling device has an engagement means for axial displacement of the coupling device along the common axis of the coupling device, and wherein the engagement means is movable along a longitudinal axis of the pipetting device. 
     
     
       15. Pipetting device according to  claim 14 , wherein the engagement means is arrangeable in different end positions driven by the actuating element. 
     
     
       16. Pipetting device according to  claim 14 , wherein the engagement means embraces a second coupling means at least in regions. 
     
     
       17. Pipetting device according to  claim 14 , wherein the engagement means and the actuating element are made in one piece. 
     
     
       18. Pipetting device according to  claim 14 , further comprising a spring means for exerting a spring force that acts on the actuating element when moving between end positions along a partial path, and wherein the spring means is arranged on the actuating element and/or on the engagement means. 
     
     
       19. Pipetting device according to  claim 14 , wherein an adjustment sleeve of the adjusting device forms the actuating element, and wherein the adjustment sleeve is rotatable about a longitudinal axis of the pipetting device for changing the stroke of the displacement device and for changing the volume indicator, and wherein the adjustment sleeve and the engagement means are mounted to rotate relative to each other and/or to be longitudinally displaceably together. 
     
     
       20. Pipetting device according to  claim 14 , wherein, for coupling the engagement means to the adjusting device, the engagement means comprises a coupling element and the adjustment means comprises a counter-coupling element, wherein the coupling element and the counter-coupling element are configured to block a rotational movement of the adjusting device during a transition from the use state to the adjustment state and/or from the adjustment state to the use state.